staging: rts5208: use msecs_to_jiffies for timeouts

This is only an API consolidation and should make things more readable

Converting milliseconds to jiffies by val * HZ / 1000 is technically
not wrong but msecs_to_jiffies(val) is the cleaner solution and handles
corner cases correctly.

Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>